A mix of satellite images, in-situ measurements and air quality models are used to detect air pollutants and guide city authorities in improving traffic management to reduce emissions.
Antwerp is the capital and the largest municipality of the Antwerp province in Flanders, Belgium. The Urban Development department of the city, depending from the Flemish Environmental Agency, is the entity in charge of monitoring air and noise pollution at the local level.
Antwerp is particularly affected by air pollution generated by the eight-lane motorway passing near the city centre, its important seaport, as well as by the presence of the second petrochemical industry worldwide. Moreover, the high buildings located in the city centre create street canyons where noise and pollutants are especially concentrated.
Every year, the Flemish Environmental Agency produces reports on the concentration levels of different pollutants (PM10, PM2.5, NO2, BC) present in city hotspots. Such reports, based on measurements at the street level, inform on the situation in previous years. However, they do not include the forecasts which the Municipality needs to devise adequate future traffic management plans to reduce emissions and noise.
The satellite solution
In 2010, the Municipality contracted VITO, a research institution, for an air pollution assessment study based on a combination of satellite images, ground sensors and air quality models. On the basis of this data, combined with the noise pollution maps of the Municipality, “black-spots” were identified, where air and noise pollution are highest. Not surprisingly, these black spots were found to occur in areas with the highest traffic concentration.
Thanks to the combination of satellite imagery and air quality models, which are able to capture relevant information on street topography, the new maps did not only provide assessments on current noise and air pollution, but also allowed city managers to make predictions about the impact of different traffic scenarios on air quality in the future.
The traffic scenario assessment system, created in 2010, allowed city managers to make predictions about the impact of different traffic scenarios on air quality in the future and to priorities areas where intervention to curb traffic was most needed.
As a result, the Municipality decided to make changes in traffic circulation and speed limits, to increase the number of eco-friendly buses, to increase supervision and regulation of industrial emissions and to create a low emission zone in the centre of Antwerp.
In the future, the municipality aims at updating these maps every five years.
“The traffic scenario assessment system based on satellite and ground measurements enables us to take better-informed decisions to improve traffic management in Antwerp”, Jan Bel, City of Antwerp, Urban Development, Energy & Environment.